Neutralizing treatment of acid oils for lubricant stocks



Patented Apr. 3, 1928.

UNITED srarss rattan lea-rear raise.

GEORGE F. OLSEN, OF LOSANG-ELES, CALIFORNIA, ASSIG-NOR'TO GENERAL PETROLEUM CORPORATION OF CALIFORNIA, A CORPORATIGN OF DELAWARE.

NEUTRALIZING- TREATMENT- OF ACID OILS FOR LUBRICANT STOCKS.

no Drawing.

As may be inferred from the above title, this invention relates particularly to the neutralization or partial neutralization of oils such as are obtainable by a gravity separation from an acid sludge; but it'should be understood that the principles of my present invention are not limited to the treatment of acid oils designed for use in the production of lubricants.

Although it is an object of my invention to provide a neutralizing treatment which is especially suitable for use upon acid oils containing waxes, such as the acid oils produced by a process set forth in my application (Case Hr) Serial No. M03323, filed October 11, 1926, entitled Method of acidifying oils for lubricant stocks, features of my present inventionare applicable also to oils which do not contain waxes, and regardless of the extent to which the previous acidification may be carried. I

It is a primary object of my invention, in which I may advantageously employ a finely divided non-aqueous alkaline neutralizing reagent (introduced subsequently to an addition of any subdivided anddrysolid which may be used for a purely physical eifectboth of the mentionedadditions being preferably made to an acid oil whose viscosity is not higher than about 100 Saybolt universal) to add to the acid oil only suiiicient alkali to neutralize any so-called mineral acidity re maining th'erein,-without appreciably attacking such naphthenic, or other organic,.

acids as may be present.

In the practice of this invention, in which I may use either a gaseous or a liquid or acreamy reagent (examples being, ammonia, NaOI-l, KOH, dry or in solution, and milk of lime) my preferred neutralizing agent may be ordinary soda ash, triturated'into a small quantity of an oil identical with or similar to that to be treated.

As will be seen from the foregoing, there need be no novelty either in the acid oil stock used, or in the neutralizingagent employed in myprocess,the outstanding feature thereof being such a. limitation of the neutralizing'step as to avoid the formation of na-phthenic and/or sulphonic salts or soaps.

It is an object ofmy invention to avoid the formation of soaps,requiring subsequent decomposition, followed by decoloriz ing steps,

Application filed Angus/5.31, 1926. Serial no. 132,801; I

It is an object of my invention to obviate the need for use of large quantities of clay, subsequently to a neutralization of acid oil, and to obviate or substantially reduce the loss of oil in such clay.

Although 1 herein emphasize the advantages of my novel process of neutralization in the production of an oil stock which, when finished, is exceptionally free from contained ordissolved soaps, calling attention also to economy in theuse of a neutralizing agent such as soda ash, or the like, introduced in an attenuated state (but preferably without an addition of water) and to an incidental avoidance of waste in clay and in oil, it is an important merit of my present invention (which may be regarded as especially suitable for use subsequently to a complete or partial acidification executed in thespecial manner set forth in my mentioned application Serial No. 140,823) that the process of the present invention tends to keep in the oil certain valued ingredients, for treatment in accordancewith steps set forth in my other copending applications, (including Case C, Serial No. 141,040, filed October 11, 1926')-on-e feature of theprocess set forth in the last mentioned case being a novel and advantageoususe of a light hydro carbon or'mixture such as an ordinary gasoline (preferably of high initial boiling point and of low endpoint) in an amountsufiicient to bring the gravity of the resultant solution to about 374L4i A. P. 1., the viscosity of the resultant mixture (comparable with that of kerosene) thereby becoming so low that undesired solids are readily .precipitable therefrom,- v

As a specific example of my invention, I may slightly thin in a so-called sweetening agitator, or the like, any appropriate batch (as, a batch from any tank or agitator, in which sludge has been separated there from,-such a batch presumably amounting to 250 to2000 barrels of acid oil) by'addi'ng thereto, if the viscosity of' the acid oil is above 100 Saybolt universal, sufficient gasoline to bring-the same approximately to this standard consistency atth-e temperature of operationf-which may he, say 70-150 'E; and/or I mayadd, without resort tov any tester calculation, suflicient ofa dried pulverulent solid (as, a suitable clay) to agglomerate and adsorb floating specks of acid-the intended efiect of this preliminary addition being purely physical, although such as practically to prevent the acid adsorbed in the clay from entering into a subsequent neutrallzing reaction; and I may then add to the acid 011 mixture, before or during blowing of the same (and without drawn samples show the known color'change in the test reagent from orange to yellow, indicating the completion of only the intended neutralization of mineral acid. In case ofa 2000 barrel batch, somewhere between 50 pounds and 250 pounds of soda ash may be required for the purpose referred to, and care should be taken not substantially to exceed the degree or point of partial neutralization referred to.

Whether or not agitation is continued for a brief period subsequent tocthe discontinuance of neutralization, this neutralization being such as to leave the naphthenicand sulfo acids substantially unattacked, any subsequent addition of decolorizing clay may be reduced to (say) one-fourth or one-half of that which has been customarily employed subsequently to a complete neutralization'of acid oil (up to a point testable by phenol 'phthaleine,an addition of alkali up to the point last referred to, being effective to produce the undesired naphthenic and sulphonic soaps; and this minimization of clay obviously implies an approximately corresponding diminution in the loss of oil therewith in a sludge. Although, as suggested in my first mentioned companion application (Case A) I may prefer, in the treatment of a material such as a Bunker B fuel oil for the production of lubricant stocks, to acidity in such manner as substantially to avoid attack upon these contained naphthenes (these being, in the case assumed, intendedto remain in a lubricant ultimately obtained) and although I may advantageously treat a partially neutralized product obtained in the general manner above described in subsequent processes involving the addition thereto of a considerable quantity of gasoline, (as

in, for example, my Case C) emphasize herein the fact that my described method of neutralization, economlcal 1n its use of neutralizing agents (and advantageous also in its simplification of subsequent steps, in

its conservation of values andin its avoidance of the production of soaps and the loss of oil in decolorizing clays) is very generally applicable in the treatment of acid oils,- whether or not diluted and/or clay-treated.

Although I have herein described a single complete embodiment of my invention, it should be understood not only that various features thereof may be independently used but also thatnumerous modifications might'be made by those-skilled in the art to which this case relates, without the slight est departure from the spirit and scope of this invention, as the same is-indicated above and in the following claims; and in connection with my present description and claims it should beclearly understood that I herein use the term acidity to include not only a hydrogen concentration due to such true mineral and/or organic acids as may be present in the oil, but to include also allied bodies naturally occurring in the oil or formed therein and therefrom during the refining process. a i i I claim as my invention;

1. In the treatment of acid oils containing organicacidity as wellas mineral acidity, a method of neutralization characterized by. the fact thata comminuted solid alkali is added in quantity suflicien't to neutralize the mineral acidity only,"said neutralizing agent being added in successive small quantities during agitation, the presence of water being avoided throughout. a

2. In the treatment of acid oils containing organic acidity as well as mineral acidity, a method of neutralization characterized by the fact that an alkali is added inquantity sufficient to neutralize'the mineral acidity only, the neutralizing agent being soda ash previously triturated in a small quantity of oil, and the presence of water being avoided throughout. 1 i

3. In the treatment of acid oils containing 7 organic acidity as well as mineral acidity,

the fact that a comminuted solid alkali is added in quantity sufiicient to neutralize such portion ofthe total acidity as is indicatedby a change from an acid to a neutral reaction when the oil is tested with an alcoholic solution of methyl orange.

In testimony whereof, I havehereunto set my hand at Los Angeles, California, this a method of neutralization characterized by 

